The worrying decline applies across all age groups but was particularly marked amongst two-year-olds, according to statistics included in the end of season league tables covering the world's best horses.

Only 18 out of 40 Group class juveniles seen in Europe last season were trained in Britain. Not only is the overall number of youngsters rated 110 or higher believed to be the smallest on record but the domestic share of 45 per cent compares to a five-year average of 55 per cent.

The domination of the two-year-old crop by Irish trainer Aidan O'Brien is a superficially obvious reason for the dramatic shift. However, the Ballydoyle factor appears to tell only part of the story as the number of French-trained youngsters to make the classifications held up remarkably well.

Of course, there is a chance the disappointing statistics for Britain's share of this elite group in Europe amount to a one-off, but the depressing figures for older horses suggest they may form part of a worrying trend which will set alarm bells ringing in Portman Square.

The proportion of top British three-year-olds within world racing has averaged 34 per cent since 1997 and topped 42 per cent three years ago, but has fallen to 26 and 27 per cent over the past two years. America enjoyed the biggest increase.

Similarly, there has been a fall for two consecutive seasons in Britain's share of leading horses aged four and above. Japan has made notable advances amongst these generations.

The panel of handicappers which assembled in London to present the International Classifications was at something of a loss when it came to identifying specific reasons for the apparent decline in the quality end of British racing although there are several plausible theories.

One is the `Godolphin factor.' By concentrating most of their two-year-old eggs in the David Loder basket, the Maktoums are dependent on the form of one yard, rather than several, and the Loder stable was not firing on all cylinders last autumn when the major prizes were up for grabs.

By the same token, some trainers are reckoned not to expose their best two-year-olds for fear that they will lose them to Godolphin.

Also the apparent change in training methods or priorities, which resulted in Sir Michael Stoute having only one top two-year-old and Henry Cecil having none for the second year running, may have a part to play.

Some handlers restrict the campaign of their `late maturing' types and concentrate on their three-year-old career. In which case, why has the proportion of top British-trained three-year-olds declined?

And then there is the prizemoney argument. Are the internationally low levels of domestic prizemoney deterring owners of the best bloodstock from having them trained in Britain as opposed to Ireland, France and America, where purses are more attractive? There will be no shortage of people keen to advance this theory but whatever the reason the decline is there for all to see.